[update] Add progress status to the update

[mirkoCrobu]

Motivation

When launching the update process (both via API and, eventually, a CLI command), we should return a progress in percentage. This could be done in many ways:

estimate the time needed for some tasks, based on previous measurements (for example, how much it usually takes to do an apt update on Imola)
When we know there is a list of tasks to do (a list of packages to update), then it's possible to use that to provide progress information
This information can then be used by the FE team (App Lab) to show a progress bar.

Change description

Additional Notes

Reviewer checklist

• PR addresses a single concern.
• PR title and description are properly filled.
• Changes will be merged in main.
• Changes are covered by tests.
• Logging is meaningful in case of troubleshooting.